The 36 gallon tank sound good, but I don't know if my bladder can hold for 630 miles assuming I get 18 mpg? Either way, I prefer a piece of mind in a zombie apocalypse scenario.

 

Perhaps a potty option to go with that 36 gallon tank?

Where the 36 gallon would really help is when towing, and getting 12mpg. The same scenario where a diesel would really shine with its extra torque and range. Then again, because the 5.7 is such a brute, I'd probably prefer the gasser as it would have better passing power (more hp) at speed, albeit with a downshift or 2 and some rpms. The diesel would make for more effortless grunt without shifting, which would be a nice thing.